Researchers at the Civil Aviation University of China and Tsinghua University built a receiver that converts green laser light into electricity at 38.49 percent efficiency, enough to spin a drone propeller on a lab bench with nothing but a beam. The study landed July 29 in Matter & Light, a Cell Press journal. I have covered wireless drone charging schemes for years at DroneXL, and this is the first one that attacks the real bottleneck: the receiver, not the laser.
A Sandwich Of Perovskite And Harvested Heat
The device is a tandem receiver the team calls a perovskite laser cell-thermoelectric unit, and its trick is refusing to waste the heat that kills every other design. A perovskite top layer converts the laser light into current, while a thermoelectric generator underneath turns the leftover heat into additional electricity instead of letting it cook the cell.
Between the two layers sit antimony selenide nanocrystals that work as thermal barriers. They conduct heat poorly on purpose, keeping the perovskite layer from degrading while the thermoelectric layer feeds on the temperature difference.
The numbers back the design. Under a green laser the receiver converted 38.49 percent of the light into electricity, among the highest figures reported for this class of device, even while the hardware ran at 176 to 194 degrees Fahrenheit (80 to 90 C) during high-power testing.
The integration is aircraft-minded too. The receiver mounts under a wing with air channels that use propeller downwash for passive cooling, so the drone’s own thrust becomes part of the thermal management.
The dual harvest is what separates this from a solar panel with a laser pointed at it. A conventional photovoltaic cell treats heat purely as an enemy. This receiver treats it as a second fuel, which is why the efficiency figure survives operating temperatures that would drag an ordinary cell downhill.
The Graveyard Of Wireless Charging Promises
Every wireless charging scheme I have covered pays what I think of as a geometry tax: the aircraft stays tethered to a location by physics instead of a cable. PowerLight beams power to fixed-wing aircraft from the ground, but the drone lives inside roughly a mile of the emitter.
The perching approaches accept the leash openly. The University of Southern Denmark started clinging drones to high-voltage lines back in 2022, using inductive coupling to sip current from the magnetic field around the cable. By 2024 that work had matured into the self-charging vampire drone, which hangs from a line for 30 minutes to six hours per charge depending on the voltage. University of Washington students won $15,000 with self-charging drones that monitor power lines by descending onto the infrastructure they inspect, a story I wrote in April 2025 and thought about immediately when this paper crossed my desk.
Laser charging itself has burned credibility before. When a Chinese team claimed a drone that could fly indefinitely on beamed light, I dug into whether the claims held up in February. The physics were real. The operational details were thin.
From Bench Test To Airborne Is The Hard Mile
The team is honest about where this stands, which the press releases in this niche rarely are. The receiver has powered a propeller on a stationary drone model. It has not flown.
Senior author Jianhua Han framed the ambition plainly: “Imagine a future where drones inspecting forests, monitoring disasters, or delivering packages no longer need to land frequently to replace batteries.”
Getting there requires the unglamorous list Han’s team laid out. The receiver has to fly on a lightweight aircraft outdoors. A tracking system has to hold a high-power beam on a moving target. Safety protocols have to exist before anyone points that beam across real airspace. None of those steps is optional, and each one is the kind of testing that separates a materials paper from an aviation program. The work was funded by the National Natural Science Foundation of China, so the follow-through has state money behind it.
DroneXL’s Take
This is a bench demo with an excellent number attached. That is not a dismissal. In this niche, the number was always the problem.
Battery life is the structural constraint of this entire industry, the thing every operator plans around and every manufacturer chases. The reason beamed power never escaped the lab is that receivers wasted most of what hit them and overheated doing it. A design that harvests its own waste heat and posts 38.49 percent is progress on the actual failure mode, not another render of a drone bathing in light.
What it does not do is cancel the geometry tax. From the Danish line-percher to the UW students’ grid drones to PowerLight’s one-mile leash, every scheme so far trades endurance for a tether to some piece of ground. A better receiver stretches the leash. It does not cut it, because a beam still needs line of sight, and a tracker still has to hold a high-power laser on a moving aircraft over places where people live. That second problem is regulatory as much as technical, and the paper leaves it fully open.
The team says the next step is an outdoor flight test on a lightweight drone. Watch for that result. A propeller spinning on a bench is chemistry. A drone staying airborne under a beam, outdoors, with the receiver at 194 F, is the moment this becomes aviation.
